A figure no less than the PM himself provides an excellent example of how to correctly interpret trend poll data.

Last September, Turnbull pointed to a long-term polling trend as part of the reason he wanted to oust Tony Abbott: "The one thing that is clear about our current situation is the trajectory. We have lost 30 Newspolls in a row. It is clear that the people have made up their mind about Mr Abbott's leadership."

Statistically, Mr Turnbull's reasoning was sound. Thirty consecutive survey results across two polls – the old Newspoll and Newspoll (by Galaxy) – is more than enough data to make conclusions about.

He could have improved the line by mentioning the almost 200 other poll results during the same period, which also showed the Coalition behind Labor.

That's because the experts always look at how each new individual poll result compares to other recent polls.

In an article for online publication Inside Story, Mr Brent wrote about the unique preference flows of the last election, including "the Palmer United Party, which seemed to come out of nowhere; a low vote for independents; and an overall independent preference flow that favoured Labor."

Mr Utting said the handling of preferences is a "key question" when looking at a pollster's results.

All the pollsters publish a two-party preferred result based on the flows of the last election.

Fairfax/Ipsos and Roy Morgan also publish a "stated preference" two-party preferred poll based on how voters say they will direct their preferences. Sometimes the two calculations lead to the same result, sometimes it is markedly different.

In any case, Mr Brent is suspicious of how much the polls actually mean between election campaigns.

"It's hypothetical about how you would vote if there was an election," he said.

"It's only during a campaign when the questions asked actually become 'How will you vote?'"

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Six public polls

There are currently six major national polls in Australia – Fairfax/Ipsos, Newspoll (by Galaxy), Galaxy, Roy Morgan, ReachTel and Essential.

These polls use a range of methods, from the traditional phone interviews of Ipsos/Fairfax through to the fully automated robo-polling of ReachTel.

​Two of these polls are relatively new – Fairfax/Ipsos and Newspoll (by Galaxy) – and untested in a national election.

They have come about because the emergence of cheaper-to-produce robo-polling hurt the traditional pollsters.

Nielsen, which had produced the Fairfax political poll since 1995, pulled out of the political polling market in mid-2014, and the Newspoll research business, which ran the "old Newspoll" for The Australian, shut down in mid-2015.

Fairfax, which publishes The Australian Financial Review, turned to international pollsters Ipsos to produce its poll, while Galaxy Research took on the Newspoll brand for The Australian.

There is debate about the accuracy of robo-polling, but companies that use the technique are confident of its accuracy.

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"If you asked me five years ago, I would have been skeptical of robo-polls," John Stirton, the former Fairfax pollster and now a research consultant, said. "But they seem to have been OK."

But Mr Utting, who uses live telephone and mobile interviews for his work for Labor, believes his is the superior method.

"It's a trade-off with budgetary considerations between robo-polls and live," he said.

"I essentially believe the best method is live telephone interviews with mobile supplements. That's the method I use and I actually think that's the best one. It's also the most expensive."

The real test of the accuracy will be against the election result.

At the last federal election there wasn't much in it. Four of the pollsters (Newspoll, Fairfax/Nielsen, Galaxy and ReachTel) were within 0.5 points of the actual two-party preferred result.

Publishing frequency changes during election campaigns, when most of the pollsters will dramatically increase the number of polls published, and even branch out in electorate and other types of polling.

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The last word can go to Simon Banks, managing director of Labor-aligned lobbyists Hawker Britton.

"The best way to understand these polls is to aggregate them, to understand they have different margins errors and to see them in trends," he said.

"An opinion is backward looking advice, so what you see over time is that gradual trends occur.

"The trend is your friend – and if any media outlet is screaming the result of one opinion poll as meaning X, Y or Z, it is invariably wrong."

Fairfax/Ipsos

National polls published monthly in The Australian Financial Review, The Sydney Morning Herald and The Age

State-based polls published sporadically in The Sydney Morning Herald and The Age

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First published: November 2014; Ipsos was founded in 1975

Methodology: Interviews via telephone and mobile

Ipsos won the tender to take over as the Fairfax pollster after Nielsen shut down its political polling arm in mid-2014.

The Fairfax/Ipsos poll is the only national political poll that still uses a traditional telephone methodology. It is a monthly poll conducted by interviewers of about 1400 voters with a margin of error of 2.6 per cent. The calls are split 70 per cent to landlines and 30 per cent to mobile phones.

Ipsos director Jessica Elgood said the methodology is superior to rivals using robo-polling because people are more willing to talk to humans than automated voice software. She cites a response rate of about one in 20 calls, or five per cent.

"The goal of good research is usually to achieve as representative a sample of the audience you are surveying as possible - in the example of political polling, this is generally a sample of the general public," she said.

"This is why the response rate matters. The lower response rate for robo-polls implies that the public are less willing to take part, suggesting that the views expressed in those surveys are less representative.

"Telephone surveys such as the Fairfax/Ipsos polls screen respondents to ensure that a representative mixture of people are interviewed - this means at the beginning of the call the interviewer will establish some key information about the potential respondent to determine whether or not they should be interviewed to achieve this demographically representative sample of Australians.

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"There is time and effort to find this representative mixture of the public – for example, while older people are more likely to be at home and more willing to take part, younger respondents are much harder to find."

Recent performance: Untested in national polls; one of four pollsters to correctly predict the two-party preferred outcome of the 2014 Victorian election; and posted a 3.7 percentage point difference (largest of the seven pollsters) in the two-party preferred outcome in the 2015 NSW election.

Newspoll (by Galaxy)

National polls published fortnightly in The Australian

First published: July 2015

Methodology: Robo-poll and online survey

Galaxy

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National and state-based polls published sporadically in the News Limited tabloids

First published: 2004

Current methodology: Robo-poll and online survey

Galaxy Research have been the pollsters for the News Limited tabloids since 2004 when David Briggs, who was the general manager at the Newspoll research company for 18 year, set up the company.

The political polls use a combination of online and robo-poll interviews for surveys.

The Galaxy national poll is published sporadically in the News Limited tabloids and have slowed in frequency since the company began running the Newspoll (by Galaxy) survey for The Australian.

The last national Galaxy survey published was in September 2015 after Malcolm Turnbull took over as Prime Minister from Tony Abbott.

That poll had a sample size of 1224 meaning a margin of error of 2.8 per cent.

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The Newspoll research company closed in mid-2015 with Galaxy Research taking over the Newspoll survey brand.

This survey, Newspoll (by Galaxy), is a twice-monthly poll conducted using a similar methodology to the traditional Galaxy survey - a combination of online and robo-poll interviews.

It has a sample size of around 1800 voters per poll and the margin of error is three per cent.

"We do not include mobiles in the robo-poll samples but we can reach those in mobile only households through the online component of the sample", said Mr Briggs.

He said the response rate is "five per cent of all numbers dialled or around 10 per cent of all answered numbers".

Newspoll (by Galaxy) has not been tested against any elections but Mr Briggs points to the performance of Galaxy polls as evidence of the survey's accuracy.

In the 2013 election, there was little difference between the final two-party preferred polls of Galaxy, ReachTel (another robo-poller), Nielsen (the previous old Fairfax pollster), the "old Newspoll" and the actual result.

"As you will observe, the accuracy of these Galaxy polls ranks as among the best of all of the published polls," Mr Briggs said.

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"The obvious conclusion that I would draw from these comparisons is that the much more expensive method of interviewer administered surveys cannot claim any greater accuracy than any other method used.

"It is for this reason that we have moved away from interviewer administered polling."

Recent performance: Newspoll (by Galaxy) - untested in national polls. Galaxy - one of four pollsters to correctly predict the two-party preferred outcome of the 2014 Victorian election; and the second most-accurate in the 2015 NSW election with a 0.7 percentage point difference to the actual two-party preferred result.

Roy Morgan

National polls published fortnightly at roymorgan.com

First published: Using current multi-modal methodology in March 2013; The late Roy Morgan began polling in the 1940s

Each fortnight the firm surveys about 2000 Australians, including approximately 1600 electors, via face-to-face interviews and another 1500-odd further voters via SMS polling.

The survey usually includes more than 3000 voters and has a margin of error of 1.8 per cent.

"This is the largest fortnightly poll undertaken in Australia, with over 3000 Australian electors, and the sample is spread across all 150 Australian electorates and adheres to the important demographic parameters of age, gender and location," said Morgan Poll Manager Julian McCrann.

"Telephone interviewing – with both landline and mobile phones – (is also) undertaken in case there are any low counts from any particular demographics to ensure the sample is evenly spread to reflect the Australian population.

"As stated, the SMS polling is done entirely via mobile phones selected at random on a fortnightly basis from a panel of tens of thousands of Australians.

"Our response rate from SMS interviewing is very high...approximately a 50 per cent response rate."

"Using several different contact methods allows us to reach all Australians rather than relying on a particular method which may skew overall polling results in unpredictable ways."

Recent performance: In the 2013 election Roy Morgan published three two-party preferred polls - a stated preference poll, a poll based on 2010 election preference flows and a poll based on Palmer how to vote cards. The stated preference flow survey was the only poll to accurately predicted the election outcome, while the 2010 preference flow poll had a one percentage point difference (the fifth largest error of the polls) and the Palmer poll had the second-largest average difference, of two percentage points, of the seven pollsters.

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ReachTEL

National polls broadcast monthly on Channel Seven and state-based polls published sporadically across a range of newspapers

First published: First national poll published in April 2013

Methodology: Robo-polling

ReachTel uses a robo-polling technology, called Voice Broadcast, to deliver pre-recorded voice calls to both landlines and mobile telephones.

"The recordings are produced by a professional voice artist and aren't synthesised," said James Stewart, the Head of ReachTEL.

"Respondents use the buttons on their telephone keypad to provide answers to questions."

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Mr Stewart said his response rates were around 20 per cent, or that one in every five calls leads to a successful interview.

"Response rates differ from electorate to electorate but a typical completion rate is around 20 per cent," he says.

"In the days and weeks prior to an election this can spike as high as 40 per cent."

The national surveys usually have a sample of around 3000 respondents with a margin of error of 1.8 per cent.

"We are using the exact same surveying techniques developed over the last 50 years and have applied technology to make it significantly more efficient," he said.

"By reducing the cost of collecting the sample, we are able to get to market quicker, gather bigger and more accurate samples and have the results delivered to our customers in a matter of hours."

Mr Stewart also believes that far from making the poll less reliable, people are more likely to be honest in a pre-recorded call.

"The automated nature of the call ensures a consistent message is heard by everyone and there is potential for a greater level of honesty when you are interacting with a robot instead of a live operator," he said.

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Recent performance: In the 2013 election ReachTel's two-party preferred results had the same average difference of 1 percentage point as the old Newspoll, the defunct Fairfax/Nielsen poll and the Galaxy poll. One of four pollsters to correctly predict the two-party preferred outcome of the 2014 Victorian election and posted the lowest percentage point difference, 0.3 points, to the two-party preferred result in the 2015 NSW election.

Essential

National polls published weekly in Crikey and The Drum

First published: 2007

Methodology: Essential uses an online panel made up of more than 1000 people. The panel is run by Your Source, a fieldwork supplier owned by market research agency Colmar Brunton, who include the political questions in a weekly national omnibus survey.

"What I think we can uniquely claim is that we are the only poll which extensively polls social and political issues," says Andrew Bunn, Essential Media's Research Director.

"Voting intention is probably the least important part of our polling.

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"We established our poll to do more than just measure a few horse race issues.

"Each week we poll a range of current social and political issues.

"Our intention is to attempt to explain and understand public opinion rather than simply measure it.

"And despite constraints of timing (our poll takes a week from question design to reporting) you will often find that we are the first poll to cover significant issues as they arise - probably because we have input from people who work in and understand politics and public issues."

Essential average their national polling over two weeks meaning their sample size is usually around 1800.

Mr Bunn said a calculated margin of error assumes "random sampling of the full population - a criteria that simply cannot be met by any poll these days". Instead he said the Essential poll's "the weighted sample is representative of the population age/gender/region distribution".

"We have made a deliberate decision to report voting intention on a 2-week rolling average," Mr Bunn said.

"I know this annoys some observers who complain about the lack of movement in our voting intention results.

"However, that's the reason we do it - to smooth out the results and counter unfounded speculation about small movements that are basically meaningless."

Recent performance: In the 2013 election, Essential had a difference of 1.5 percentage points from the actual two-party preferred result.